[mythtv] Problem with commit 9506b88 2017/10/09 : Cleanup gcc and clang warnings generated by -Wextra switch.

[Paul Harrison]

On 25/10/17 05:29, David Hampton wrote:

> Hi Peter,
>
> I was afraid you were going to say that it was that cleanup commit.
> That was an aggregation of 124 smaller commits over probably six
> months.  Given that Myth works on your AMD system and my x86 systems,
> my guess would be that it is probably in a change to one of the openmax
> files.
>
> I've looked at the changes to files with 'omx' in the name and nothing
> stands out to me as possibly being a problem.  There appear to be only
> four patches that modify five 'omx' files.  I've uploaded those patches
> to http://love2code.net/mythtv/ if you want to try reverting them and
> see if that fixes the crashing.
>
> I have a RPi Model B+ v1.2 that was given to me but I've never powered
> it on.  Would this be sufficient for me to use to try and bisect the
> problem?  I'd probably need some help in getting the RPi set up.  (Is
> it possible to cross-compile for AMD on an x86 system, or would I need
> to run native compiles on the RPi itself?)
>
> I didn't realize that git didn't push all my intermediate nodes when I
> pushed a merge, but that makes sense.  I will certainly write merge
> notes more carefully going forward.
>
> David
>
> P.S.  I could also revert the aggregate patch, and then rebase and
> reapply the 124 individual patches.  That would make the individual
> changes visible to everyone.
>
>
>
> On Tue, 2017-10-24 at 22:38 -0400, Peter Bennett wrote:
>> Hi David
>>
>> The above mentioned commit is a merge of hundreds of changes. It is
>> causing memory corruption errors on Raspberry Pi, consistently every
>> time you try to play a recording. You get one of these errors and a
>> core
>> dump:
>>
>> corrupted size vs prev size
>> smallbin double link list corrupted
>> free(): invalid pointer
>>
>> These occur in malloc and free at different places each time. AMD64
>> systems are not affected although the codebase is the same.
>>
>> Compiling from aea96ba which is the immediately prior commit, is
>> fine.
>> Compiling from 9506b88 which is immediately after that commit, gives
>> those errors, as does compiling from the latest.
>>
>> I cannot compile any of the intermediate commits between those two,
>> because they are off your repository, do not contain the Raspberry
>> Pi
>> Stretch changes, and thus fail compilation.
>>
>> Do you know which change may be causing this problem? We may have to
>> roll back this set of changes.
>>
>> Peter
>>
>>

I could do another coverity build if you think it may help. The last run 
did pickup a use after free but I think that was in the crystalhd 
decoder which no one cares about.

Paul H.